Table of Contents
Advertisement
TYPE 1391-B PULSE, SWEEP, AND TIME-DELAY GENERATOR
from center, reset C321 and repeat the 6-psec adjust-
or SO602 (yellow wire). It should read 3 0 0 f 1 volts; if not, ad-
ment (R330), and readjust the 3-psec and 12-psec
just R612.
ranges.
b. T o check the compensation adjustment, buck most of the
300 volts out with either a 300-volt battery or a second 300-volt
Generally, when V303 is replaced, only C321 must be retouched
regulated power supply. This will permit the voltmeter to be used
to restore proper operation to the 3-, 6- and 12-psec ranges.
in differential connection on its 1- or 5-volt scale. (The 3300-
3.6 POWER-SU,PPLY ADJUSTMENTS.
volt Type 1391-B supply can be offset by either 1 or 2 volts to
3.6.1 TEST EQUIPMENT. The minimum test equipment neces-
sary for the correct adjustment of the power supply includes:
a. a 300-v battery or regulated power supply s e t for 300v,
b. a 5- or 10-amp ~ariac@autotransfonner or equivalent,
c. an accurate a-c voltmeter to set line voltage,
d. a wattmeter with 500-watt scale,
e. a volt-ohmmeter with 20,000-ohm/volt sensitivity (Wes-
ton 772 Analyzer or equivalent).
f. additional apparatus, useful though not absolutely neces-
sary, includes either a wave analyzer (General Radio Type
736-A or equivalent) or a Distortion and Noise Meter (General
Radio Type 1932-A or equivalent).
3.6.2 INPUT POWER CHECK. The Type 1391-B requires 420
watts a t 115 volts, 60 cycles.
3.6.3 300-VOLT REGULATOR ADJUSTMENT.
a. Measure the 300-volt power supply a t pin 2 of plug PL401
permit the meter to read upscale.)
Now vary the line voltage to the Type 1391-B over the
105-125 (210-250)volt range. Note that a s linevoltage increqses
10 percent the regulator output decreases by 0.5 to 1 volt and
vice versa. If the compensation curve is not symmetrical about
the 300-volt center, readjust R607 to make it so. R612 might
need readjustment to maintain correct output voltage.
3.6.4 -150-VOLT ADJUSTMENT. R618 should be s e t to pro-
duce -150volts output a t pin 6 of plug PL401, with input voltage
s e t a t 115 volts.
3.6.5 -400-VOLT ADJUSTMENT. Adjust the PULSE DURATION
and sweep timing controls to produce a 25-millisecond pulse a t
a 20-cps repetition rate. Set the PULSE AMPLITUDE control to
maximum and s e t the output impedance for the highest-amplitude
negative pulse whose negative edge can be seen on the screen.
Set R618 for minimum line-frequency ripple on the "bottom" of.
this pulse a s the line voltage is varied from 105 to 125 volts.
Advertisement
Table of Contents
